Leaf thermal safety margins decline at hotter temperatures in a natural warming 'experiment' in the Amazon.

Autor: Kullberg AT; Department of Biology, University of Miami, Coral Gables, FL, 33146, USA., Coombs L; Hussman Institute of Human Genomics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA., Soria Ahuanari RD; Herbario Regional de Ucayali IVITA, Pucallpa (HRUIP), Universidad Nacional Mayor de San Marcos, Pucallpa, 25001, Peru., Fortier RP; Department of Biology, University of Miami, Coral Gables, FL, 33146, USA., Feeley KJ; Department of Biology, University of Miami, Coral Gables, FL, 33146, USA.; Fairchild Tropical Botanic Garden, Coral Gables, FL, 33156, USA.
Jazyk: angličtina
Zdroj: The New phytologist [New Phytol] 2024 Feb; Vol. 241 (4), pp. 1447-1463. Date of Electronic Publication: 2023 Nov 20.
DOI: 10.1111/nph.19413
Abstrakt: The threat of rising global temperatures may be especially pronounced for low-latitude, lowland plant species that have evolved under stable climatic conditions. However, little is known about how these species may acclimate to elevated temperatures. Here, we leveraged a strong, steep thermal gradient along a natural geothermal river to assess the ability of woody plants in the Amazon to acclimate to elevated air temperatures. We measured leaf traits in six common tropical woody species along the thermal gradient to investigate whether individuals of these species: acclimate their thermoregulatory traits to maintain stable leaf temperatures despite higher ambient temperatures; acclimate their photosynthetic thermal tolerances to withstand hotter leaf temperatures; and whether acclimation is sufficient to maintain stable leaf thermal safety margins (TSMs) across different growth temperatures. Individuals of three species acclimated their thermoregulatory traits, and three species increased their thermal tolerances with growth temperature. However, acclimation was generally insufficient to maintain constant TSMs. Notwithstanding, leaf health was generally consistent across growth temperatures. Acclimation in woody Amazonian plants is generally too weak to maintain TSMs at high growth temperatures, supporting previous findings that Amazonian plants will be increasingly vulnerable to thermal stress as temperatures rise.
(© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.)
Databáze: MEDLINE
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